Proton Source

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Proton Source

• Eric Prebys FNAL Accelerator Division/Proton
  Source

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The Fermilab Accelerator Complex
Proton Source
MinBooNE
NUMI
MI-8 line
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Preac(cellerator) and Linac
New linac (HEL)- Accelerate H- ions from 116
MeV to 400 MeV
Preac - Static Cockroft-Walton generator
accelerates H- ions from 0 to 750 KeV.
Old linac(LEL)- accelerate H- ions from 750 keV
to 116 MeV
4
Booster

• Accelerates the 400 MeV beam from the Linac to 8
  GeV
• Operates in a 15 Hz offset resonant circuit
• Sets fundamental clock of accelerator complex
• From the Booster, beam can be directed to
• The Main Injector
• MiniBooNE (switch occurs in the MI-8 transfer
  line)
• A dump.
• More or less original equipment

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Extracted Beam Structure
Single turn extraction
80 bunches 1.6 msec
19 ns
9 ns (FW)

• 5-6 x 1010 protons/bunch x 80 bunches 4-5 x
  1012 protons/batch
• (instantaneous) batch rep rate 15 Hz

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Limits to Proton Intensity

• Total proton rate from Proton Source
  (LinacBooster)
• Booster batch size
• 4-5E12 protons/batch, depending on beam quality
  required.
• Booster repetition rate
• 15 Hz instantaneous
• Currently 9Hz, limited by RF system.
• Beam loss
• Damage and/or activation of Booster components
• Above ground radiation
• Present performance
• Maximum 1017 p/hr _at_ 4.5x1012 p/batch

Historically our biggest worry
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8 GeV Targetry Possibility Booster Neutrino Beam

• Could locate target somewhere in MI-12B beam line
• Would compete with running experiments for beam

8
Variable Energy??

• The specification says 1-5 GeV
• The Booster Accelerates resonantly to 8 GeV
• It cannot be changed on a cycle by cycle basis
• It can (and has) accelerated to different
  energies during dedicated running periods,
  HOWEVER
• The MI-8 transfer line consists largely of
  permanent magnets design for 8 GeV beam.
• Cannot transport lt8 GeV beam to Main Injector or
  BNB

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Possibility Booster Dump
MI-8 Line

• Used for study cycles and short batches
• Can run to here with Main Injector in access
• No permanent magnets before dump.
• Could be retuned for alternate energies during
  special running periods.
• Limited space for apparatus.
• Maximum beam flux 6.8 x 1018 protons per year
• And we need a lot of that for normal operation.

Dump line
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Extraction Aperture

• Probably cant go below 4 GeV without big losses

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A Few Comments on Proposed Parameters

• Proton energy 1 GeV - 5 GeV
• Protons per macro-pulse 1017
• 20000 times Booster capacity
• 1000 times SNS or (proposed) JPARC storage
  rings
• -gt Slow spill not an option here or anywhere
• Nominal macro-pulse lengths lt 1 msec
• If linac, then 16 Amps 100-1000 times practical
  linacs
• Variable macro-pulse spacing up to 250 sec
• 1017 proton _at_ 5GeV every 250 sec 320 kW
• 1/4 design SNS
• About 10 times TOTAL Fermilab proton capacity